Chromatography column and method of maintenance

ABSTRACT

A chromatography column and method of maintenance is described which does not require the use of a hoist or crane for disassembly. The method provides improved operator safety by reducing the need for the operator to work below a suspended or supported load within the column. Furthermore, the removal or replacement of column components is facilitated by providing access to the interior of the column and by the provision of a handling device.

FIELD OF THE INVENTION

The present invention relates to chromatography columns and methods foroperating columns in industrial-scale chromatography. In particular, theinvention is concerned with chromatography columns and safer methods forperforming maintenance on such columns, such as cleaning and replacingbed support plates, distributors, media retaining meshes and O-rings,without the need for heavy lifting equipment such as hoists or cranes todismantle the columns.

BACKGROUND OF THE INVENTION

Chromatography columns may be used in industrial processes to purifyprocess liquids and separate substances of interest from processliquids; typical examples include large-scale preparative purificationof fine chemicals and pharmaceuticals, together with biologicalproducts.

Industrial-scale chromatography columns typically comprise a hollow,axially vertical tubular housing including a liquid inlet at the upperend and through which the buffer and substances to be separated aredispensed to the media bed located within the cavity of the tube, and aliquid collecting system at the lower end for collecting substances andbuffer. The particulate chromatographic media or bed through which thebuffer fluid and/or substances to be separated and purified percolatesis located between the liquid inlet and collecting system.

An adapter assembly is typically affixed to the upper end of the tubularhousing and a base assembly to the lower end where it is bolted to thebottom flanges. Each of these assemblies typically comprises a strongbacking plate and a distributor plate which further supports a layer ofmesh, sinter or other fluid-permeable media-retaining material whichpermit process liquid flow into and out of the chromatography bed spaceor cavity while retaining the bed of particulate medium. To provideadjustability and control of the bed height and bed compression, theadapter assembly is typically made in the form of a piston or slidingadapter in the column tube interior. After the column is charged withbed media, typically through a nozzle, the adapter may be forced towardthe bottom of the tube to compress or pressurize the media bed.Generally the base assembly is a fixed structure which is bolted againstthe bottom flange of the column tube but, in some instances, may also bein the form of a movably slidable piston or adapter.

The backing plate of the base assembly generally acts as a support forthe column, being itself supported on legs or some other standarrangement which allows clearance for outlet pipework projectingbeneath the base assembly.

When such a column requires maintenance to, or cleaning of, internalcomponents, such as the valves, seals, meshes/screens, distributionsystems etc., heavy lifting gear such as a crane or hoist is necessaryto lift the upper end/adapter assembly away from the column tube and thecolumn tube away from the lower end/base assembly as these assembliescan weigh in excess of three tons. The use of heavy overhead liftingequipment to disassemble the column in order to carry out internalmaintenance is not desirable. Operator safety is obviously a concernwhen heavy equipment is lifted overhead and technicians exposed below.Furthermore, alignment structures are required to keep the column andits base/adapter assemblies axially aligned as they are separated fromeach other, to avoid damage to the precision components.

The presence of such alignment and lifting structures imposessignificant obstructions around the tube and need to be carefully laidout to provide sufficient clearance at some point of the circumferencefor insertion/removal of the internal components. Furthermore, therequirement to use heavy lifting equipment imposes constraints onhousing such columns, sufficient overhead space and support beingrequired to accommodate hoists or cranes. As many chromatography columnsare now run in “clean” environments, to avoid microbiologicalcontamination, where it is extremely difficult to accommodate overheadequipment, the requirement of moving the column to another room fordisassembly and maintenance is problematic. This problem is exacerbatedby the need to clean and verify the column before returning it for useto the clean environment.

U.S. Pat. No. 6,736,974 addresses some of the above problems byproviding a column which is capable of lifting the adapter assemblyabove the column tube and/or raising the column tube above the baseassembly by means of an hydraulic system which is integral to thecolumn.

However, the system described in U.S. Pat. No. 6,736,974 has significantdisadvantages associated with it by virtue of its design. As can be seenfrom FIGS. 4 and 5 of U.S. Pat. No. 6,736,974 and described in column 4,lines 63-66 of that document, in order to remove the distributor plate(31) and/or mesh (28/60) from the interior of the column, the operatormust work within the centre of the drum (18) to access and remove thefixing nut (30) which secures these component parts. As industrialcolumns typically have diameters ranging from about 200 mm to 2000millimetres, this means that the operator must work below a suspended orsupported load to unscrew the nut. This clearly poses a significantsafety risk to the operator, particularly where the operator's arm orhead is exposed below the suspended or supported load.

Furthermore, once the column tube/cylinder or adapter assembly has beenraised from the base assembly or tube, respectively, removal of theheavy bed support plate, distributor plate or mesh from the column canonly be accomplished by tilting the plate or mesh at an angle tonegotiate the hydraulic drive pistons or safety rods. This can clearlybe seen from, for example, FIGS. 3, 4 and 5 in which the distancebetween any two safety rods (69) or between any two hydraulic pistons(36) is less than the diameter of the mesh (28/60) or distributor plate(31). The same problem would exist for the base or adapter bed supportplate (not shown). Removal of these internal components, which couldweigh in excess of 100 kg, requires considerable manhandling by theoperator and necessitates their being exposed below the suspended columnor adapter assembly. Once again, this represents a significant safetyrisk for the operator.

The task of physically removing the heavy bed support plate ordistributor plate, as described in U.S. Pat. No. 6,736,974, must becarried out by an operator, there being no disclosure of the use of anylifting aid to assist in this task. The configuration of the hydraulicpistons and the safety rods, and the need to tilt the plates in order toavoid hitting these supporting structures in withdrawing the plates fromthe column, would require the design of a bespoke lifting device.

WO 2005/056156 (Euroflow (UK) Limited) also discloses a column which canbe accessed for maintenance without the need for a crane or hoist. Thecolumn is designed such that the tube and the base assembly can beseparated by means of hydraulic drive cylinders to provide an accessspace between them to conduct maintenance or service on the baseassembly. The piston of the adapter assembly can be advanced through thecolumn tube to expose it at the open end of the column tube, i.e. in thespace between the tube and the base assembly, for maintenance.

However, as is evident from this document (for example, FIGS. 19 and 20and related description on page 23) access to release the fasteningscrews retaining the mesh in place is provided by the space between thetube and the base assembly. Removal of the meshes necessitates theoperator being exposed to a suspended load while retaining screws areremoved. Furthermore, the distance between any two drive cylinders formaintenance access is greater than the diameter of the bed supportassembly (see, for example, FIG. 7), which requires the operator tomanhandle and tilt the mesh or bed support when removing or replacingit. Maintenance of the column thus imposes a significant safety risk forthe operator.

Accordingly, a need exists to improve the maintenance methods availablefor chromatography columns by providing columns which are safer andeasier for operators to use and which do not expose them to a suspendedor supported load.

SUMMARY OF THE INVENTION

The present invention recognises and addresses these needs and others.

In a first aspect of the present invention, there is provided a methodfor conducting maintenance on a chromatography column comprising thesteps of:

-   -   a) providing a chromatography column comprising:        -   a dispersion system comprising a nozzle including a mobile            phase pathway connected to a liquid inlet;        -   a tube with an adaptor assembly connected to a drive system,            said adapter assembly moveable within a cavity of said tube            in an operational mode;        -   the adapter assembly comprising a backing plate, a            distributor and a bed support assembly fastened to each            other by releasable fixing means,        -   said drive system comprising one or more cylinders;        -   a collection system opposing the dispersion system; and        -   one or more seals;    -   b) disconnecting the adapter assembly from the tube;    -   c) lifting the adapter assembly above the tube with the drive        system to provide a gap for access therebetween;    -   d) unfastening the bed support assembly from the distributor and        the backing plate by releasing the fixing means without        accessing said gap;    -   e) removing the bed support assembly from the column;    -   f) conducting maintenance on the column and/or the bed support        assembly and/or said one or more seals;    -   g) returning the bed support assembly to the column and        fastening the bed support assembly to the distributor and the        backing plate; and    -   h) lowering the adapter assembly with the drive system to an        operational position within the tube and reconnecting the        adapter assembly to the tube.

The gap provided for access between the adapter assembly and the tube isat least three inches in height in order to permit removal of the bedsupport assembly from the column or return thereto. Preferably the gapis at least six inches in height to allow for greater access to thecolumn. More preferably the gap is at least nine inches in height. Morepreferably the gap is at least twelve inches in height. More preferablythe gap is at least fifteen inches in height. Most preferably the gap isat least eighteen inches in height.

In a preferred aspect, the fixing means are releasable from the exteriorface of the backing plate. This reduces the exposure of the operator toa suspended or supported load as they do not need to enter the gap.

In a particularly preferred aspect, the drive system comprises at leasttwo cylinders and the distance between any two said cylinders formaintenance access is greater than the diameter of the bed supportassembly. This permits the use of a handling device to support andremove or replace the bed support and/or distributor from/to the column.

Preferably cylinders are externally mounted to the column. Thisfacilitates greater spacing between the cylinders. More preferably, eachsaid cylinder is independently removable from the column.

Preferably, the step of removing the bed support assembly is carried outwithout substantially tilting the bed support assembly. This reducesoperator exposure beneath the suspended load and facilitates manhandlingand/or mechanical handling of the bed support assembly. The term‘without substantially tilting’ as used herein means ‘tilting at anangle of no more than 5° to the horizontal’.

More preferably, the step of removing the bed support assembly withoutsubstantially tilting the bed support involves use of a handling device.More preferably, the handling device comprises at least one arm and themethod comprises supporting the bed support assembly on at least one armof the handling device.

Optionally, the step of conducting maintenance on the column furthercomprises removing the distributor without substantially tilting saiddistributor. The term ‘without substantially tilting’ as used hereinmeans ‘tilting at an angle of no more than 5° to the horizontal’. Itwill be understood that the distributor and the bed support assemblycould be removed together and at the same time.

Preferably, the column further comprises a locking system, the methodfurther comprising the step of locking the adapter assembly with saidlocking system after lifting the adapter assembly above the tube withthe drive means. This provides for greater operator safety.

According to a second aspect of the present invention, there is provideda method for conducting maintenance on a chromatography columncomprising the steps of:

-   -   a) providing a chromatography column comprising:        -   a dispersion system comprising a nozzle including a mobile            phase pathway connected to a liquid inlet;        -   a tube with an adapter assembly and a base assembly            connected to a drive system,        -   said adapter assembly moveable within a cavity of said tube            in an operational mode;        -   the base assembly comprising a backing plate, a distributor            and a bed support assembly fastened to each other by            releasable fixing means,        -   said drive system comprising one or more cylinders;        -   a collection system opposing the dispersion system; and        -   one or more seals;    -   b) releasing the tube from the base assembly;    -   c) lifting the tube and the adapter assembly above the base        assembly with the drive system to provide a gap for access        therebetween;    -   d) unfastening the bed support assembly from the distributor and        the backing plate by releasing the fixing means without        accessing said gap;    -   e) removing the bed support assembly from the column;    -   f) conducting maintenance on the column and/or the bed support        assembly and/or said one or more seals;    -   g) returning the bed support assembly to the column and        fastening the bed support assembly to the distributor and the        backing plate; and    -   h) lowering the tube and the adapter assembly with the drive        system and reconnecting the tube to the base assembly.

The gap provided for access between the tube and adapter assembly andthe base assembly is at least three inches in height in order to permitremoval of the bed support assembly from the column or return thereto.Preferably the gap is at least six inches in height to allow for greateraccess to the column. More preferably the gap is at least nine inches inheight. More preferably the gap is at least twelve inches in height.More preferably the gap is at least fifteen inches in height. Mostpreferably the gap is at least eighteen inches in height.

Preferably, the fixing means are releasable from the exterior face ofthe backing plate. This reduces the exposure of the operator to asuspended load as they do not need to enter the gap.

Preferably, the cylinders are externally mounted to the column. Thisfacilitates greater spacing between the cylinders. More preferably, eachsaid cylinder is independently removable from the column.

Preferably, the distance between any two said cylinders for maintenanceaccess is greater than the diameter of the bed support assembly. Thispermits the use of a handling device to support and remove or replacethe bed support and/or distributor from/to the column. Maintenanceaccess is the access to the column and its component parts such as thebed support and/or distributor which is required in order to carry outmaintenance or service.

Preferably, the step of removing the bed support assembly is carried outwithout substantially tilting the bed support assembly. This reducesoperator exposure beneath the suspended load and facilitates manhandlingand/or mechanical handling of the bed support assembly. The term‘without substantially tilting’ as used herein means ‘tilting at anangle of no more than 5° to the horizontal’.

Preferably, the step of removing the bed support assembly involves useof a handling device. More preferably, the handling device comprises atleast one arm and the method comprises supporting the bed supportassembly on at least one arm of the handling device. More preferably,the method comprises releasably affixing the outer rim of the bedsupport assembly to at least one arm of said handling device.

Optionally the step of conducting maintenance on the column furthercomprises removing the distributor without substantially tilting saiddistributor. The term ‘without substantially tilting’ as used hereinmeans ‘tilting at an angle of no more than 5° to the horizontal’. Itwill be understood that the distributor and the bed support assemblycould be removed together and at the same time.

Preferably, the column further comprises a locking system, the methodfurther comprising the step of locking the adapter assembly and the tubeabove the base assembly with said locking system after lifting saidadapter assembly and the tube with the drive means. This provides forgreater operator safety.

According to a third aspect of the invention, there is provided achromatography column comprising:

a dispersion system and a nozzle including a mobile phase pathwayconnected to a liquid inlet;

a tube with an adapter assembly and a base assembly connected to a drivesystem having at least one cylinder,

said adapter assembly moveable within a cavity of said tube in anoperational mode;

the adapter assembly comprising a backing plate, a distributor and a bedsupport assembly fastened to each other by releasable fixing means;

the base assembly comprising a backing plate, a distributor and a bedsupport assembly fastened to each other by releasable fixing means;

a collection system opposing the dispersion system; and

one or more seals;

wherein the fixing means fastening the backing plate, distributor plateand bed support of the adapter assembly or the base assembly to eachother are releasable from the exterior face of the backing plate.

Preferably, the drive system comprises at least two cylinders and thedistance between any two said cylinders for maintenance access isgreater than the diameter of the bed support assembly. This permits theuse of a handling device to support and remove or replace the bedsupport and/or distributor from/to the column. Maintenance access is theaccess to the column and its component parts such as the bed supportand/or distributor which is required in order to carry out maintenanceor service.

Preferably, the adapter assembly is disconnectable from the tube and thedrive system is capable of lifting the adapter assembly above the tubeto provide a gap for maintenance access. The gap provided for accessbetween the adapter assembly and the tube is at least three inches inheight in order to permit removal of the bed support assembly and/or thedistributor from the column or return thereto. Preferably the gap is atleast six inches in height to allow for greater access to the column.More preferably the gap is at least nine inches in height. Morepreferably the gap is at least twelve inches in height. More preferablythe gap is at least fifteen inches in height. Most preferably the gap isat least eighteen inches in height.

Preferably, the tube and the adapter assembly are disconnectable fromthe base assembly and the drive system is capable of lifting the tubeand the adapter assembly above the base assembly to provide a gap formaintenance access. The gap provided for access between the tube and theadapter assembly and the base assembly is at least three inches inheight in order to permit removal of the bed support assembly and/or thedistributor from the column or return thereto. Preferably the gap is atleast six inches in height to allow for greater access to the column.More preferably the gap is at least nine inches in height. Morepreferably the gap is at least twelve inches in height. More preferablythe gap is at least fifteen inches in height. Most preferably the gap isat least eighteen inches in height.

Preferably, the drive means comprises at least two hydraulic cylindersand most preferably three hydraulic cylinders. Other drive meansinclude, for example, electrical or pneumatically powered cylinders.

Preferably, the drive means is external to the column.

Preferably, the column additionally comprises a locking system forsecuring the raised adapter assembly above the tube. This improvesoperator safety.

Preferably, the column additionally comprises a locking system forsecuring the raised tube and adapter assembly above the base assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings in which:

FIG. 1 shows an embodiment of a column known in the art in a firstmaintenance position in cross sectional view.

FIG. 2 is a cross sectional view showing the same embodiment of thecolumn of FIG. 1 in a second maintenance position.

FIG. 3 is a schematic exploded front view of an embodiment of thepresent invention.

FIG. 4 a is a schematic front view of a column in accordance with theinvention; FIG. 4 b is a side sectional view of the column of FIG. 4 a;and FIG. 4 c is a top plan view of the column of FIG. 4 a.

FIG. 5 a is a front perspective view showing the adapter assembly raisedand secured into position to provide a gap for access; FIG. 5 b showsremoval of the fastening means securing the backing plate to thedistributor and bed support assembly.

FIG. 6 is a perspective view of a handling device used to remove/inserta distributor or a bed supports from/into a column in accordance withthe invention.

FIG. 7 a and FIG. 7 b are perspective views of the column of FIG. 5showing the removal of securing rods which fasten the bed supportassembly to the distributor and backing plate.

FIG. 8 a and FIG. 8 b are perspective views showing the removal of thebed support from the column.

FIG. 9 a is a perspective view of a column with an inset showing alocking system in accordance with the invention; FIG. 9 b shows thecolumn tube raised above the base and in the process of being lockedinto position.

FIG. 10 is a perspective view of a column with the column tube raisedand locked into position in readiness for maintenance.

FIG. 11 a and FIG. 11 b illustrate the process of removing the bedsupport from the column using a handling device.

FIG. 12 shows the bed support having been removed from the column inreadiness for maintenance.

FIG. 13 is a perspective view of the column of FIGS. 10 and 11 with thecolumn tube lowered awaiting bolting to the base.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is concerned with a method and apparatus forenabling maintenance within a chromatography column. FIG. 1 shows acolumn 10 known in the art and described in U.S. Pat. No. 6,736,974which permits maintenance within a chromatography column without theneed for a hoist or crane. The column 10 comprises an elongated hollowcylindrical housing 12, or tube, having a dispersion system 14 at thetop and a collection system 16 at the bottom. The dispersion system 14includes a cylindrical drum 18 having an upper cylindrical plunger heador adapter 20 formed at the lower or interior end (i.e. interior to thecolumn). The adapter 20 is normally disposed within the upper portion oftube 12 such as is illustrated in the first operational position ofFIG. 1. The adapter 20 may be moved by a drive system 34 such as thehydraulic arrangement shown in FIG. 1. The movement of the adapter 20allows for the compression of chromatography media in order to produce apacked media bed of the optimum height within the column; a cavity 22 isformed between the dispersion and collection systems 14, 16 and/orbetween the adapter 20 and the base 64.

The dispersion system 14 may include a mobile phase pathway connected toa liquid inlet 24 together with an inlet manifold 26 to distributeincoming liquid throughout a top portion of a media bed contained withinthe cavity 22. An inlet screen 28 or filter is attached to the adapter20 by connectors and/or by an inner clamp nut 30 which is accessiblefrom the cavity 22. The screen 28 may be removed for maintenancepurposes by release of the clamp nut 30; the distributor plate 31 mayalso be removable (see U.S. Pat. No. 6,190,560 for a description of adistributor plate design).

A drive system is used to move the adapter 20 in an operational mode.The drive system is comprised of at least one and preferably three ormore, drive cylinders 34. The drive cylinders 34 move drive pistons 36which are coupled to the drum 18. A portion of the drive pistons 36 mayby threaded 38 to allow for the drive piston 36 to connect or couple toconnection arms 40 at specific locations relative to the drive piston 36such as with nuts 42, 44.

FIG. 1 shows a first maintenance position of the adapter 20 wherein theadapter 20 is raised a predetermined distance from a top 54 of thecavity 22 within the cylinder by means of the drive system 34 and piston36. The operator is thereby provided access with a hand to the centre ofthe drum 18 to release or affix nut 30 which retains the distributorplate 31 and screen 28 to the adapter 20. The distributor plate 31 andor/screen 28 may then be removed for maintenance. These are thenreplaced by affixing them to the adapter 20 and the adapter 20 may belowered to return to an operational mode, nuts 42, 44 being reset to aproper operational configuration, if necessary.

In order to perform a second maintenance operation, such as removal ofthe lower screen 160 which is typically positioned so that its outeredge 162 is between the tube 112 and the collection system 116, the tube112 may be raised by the drive system as illustrated in FIG. 2. Thebolts which normally secure the tube 112 to the base 164 are removed,and the nuts 142, 144 may be coupled to the piston 136 to drive the tube112 along with the drum 118 upwards as shown. A gap is thus providedwhich allows access for an operator to loosen nut 132, which affixes thelower screen 160 to the base 164, and remove the screen 160 formaintenance. Once maintenance has been completed, the screen 160 isreplaced, affixed by nut 132 to the base 164 by the operator, and theprocess reversed to lower tube 112 and the drum 118 into an operationalposition.

The present invention will now be described with reference to FIGS. 3 to13; FIGS. 3 to 8 relate to providing access to the upper adapterassembly and FIGS. 9 to 13 to providing access to the base assembly formaintenance.

FIG. 3 is a schematic exploded front view of a column in accordance withthe invention. The column is made of strong, inert materials such asstainless steel and other materials which are suitable for use in a GMPenvironment typical of the pharmaceutical industry. The column 210 issupported on legs 204 having feet 206 which are adjustable in order tomodify the height and/or the level of the column. The legs 204 supportthe column 210 which comprises a cylindrical housing or tube 212separating a base assembly 263 at one end from an adapter assembly 215at the other. The tube 212 may typically be made from stainless steel,or other strong, inert materials. Adjacent to the adapter assembly 215is a dispersion system comprising a nozzle 211 which includes a mobilephase pathway, for the introduction of buffer or other suitable mobilephase liquids or chemicals/materials to be separated, and a liquid inlet209. The tube 212 may be connected to the adapter assembly 215 and baseassembly 263 by a drive system having one or more cylinders 234. Thedrive system may be a hydraulic system, as shown, or may be powered byother suitable means, such as pneumatic or electrical means. The adapterassembly 215 is moveable within a cavity 222 of the tube 212 in anoperational mode, for example, to pack or compress the bed ofchromatographic media used to effect chromatographic separation ofchemicals within the column. The adapter assembly 215 comprises anadapter flange 217, one or more distance pillars 219, a backing plate220 made typically of stainless steel, a distributor 231 which may takethe form of a plate having many channels to effect the even distributionof liquids, and a bed support assembly 221 comprising a screen or meshor filter and optionally a sealing ring (e.g. 229). The bed support maybe made of an inert plastic or metal material such as stainless steel.The backing plate 220, distributor 231 and bed support assembly 221 arefastened to each other by releasable fixing means (not shown). Typicalreleasable fixing means include, but are not limited to, a screw, a nutor a clamp. The fixing means 230 may only be accessed and thus releasedfrom the exterior face of the backing plate 220, that is the face of theplate furthest away from the cavity 222. In the present example, thenozzle 211 must first be removed to provide access to the fixing means230. Additional releasable fixing means, accessible from the exteriorface of the backing plate, may optionally be employed to fasten thebacking plate, distributor and bed support assembly together. Thesefixing means can take the form of bolts inserted through correspondingholes around the perimeter of the components. Access from the exteriorface of the backing plate avoids unnecessary exposure of the operator toa suspended or supported load within the column.

The base assembly 263 comprises a backing plate 264, a distributor 266and a bed support assembly 268 fastened to each other by releasablefixing means 269. The bed support assembly 268 comprises a screen ormesh or filter and optionally a sealing ring (e.g. 274). The bed supportmay be made of an inert plastic or metal material such as stainlesssteel. Releasable fixing means 269 are, for example, a screw, a nut, abolt or a clamp; it will be appreciated that other releasable fixingmeans are also possible. As can be seen from the figure, the fixingmeans 269 secures bed support assembly 268 and the distributor 266 tothe backing plate 264 through a central hole in each component. Thefixing means 269 is only accessible and may therefore only be releasedfrom the exterior face of the backing plate 264. In FIG. 3, nozzle 272must first be removed to provide access to release fixing means 269.Additional releasable fixing means, accessible from the exterior face ofthe backing plate, may optionally be employed to fasten the backingplate, distributor and bed support assembly together. These fixing meanscan take the form of bolts inserted through corresponding holes aroundthe perimeter of the components. Access from the exterior face of thebacking plate 264 avoids operator exposure beneath a suspended load,were access only to be available from within the interior of the column.

It will be understood that separation of chemical or biologicalmaterials on the column, when the tube 212 is full of chromatographicmedia, can be carried out in either a downward or upward flow. Thus, ina downward flow, liquid containing chemical or biological materials tobe separated, is introduced through nozzle 211 and moves in a downwarddirection through the bed of media, to be collected in the collectionsystem at the base of the column via an outlet port (not shown). Inupward flow mode, liquid containing materials to be separated isintroduced via the bottom nozzle 272 and flows upwards through the mediabed to be collected at the top of the column via an outlet port (notshown). In the interests of clarity, the maintenance or servicing of thecolumn will be described in downward flow mode.

In order to conduct maintenance on the adapter assembly 215 ordistributor 231, the adapter assembly 215 is disconnected from thecolumn tube 212 by unscrewing the nuts which join the adapter flange 217to the upper column flange 213 a. The drive system then raises theadapter assembly 215 by means of cylinders 234 to allow for access tothe interior of the column for maintenance or service. The adapterassembly 215 is locked into position by means of locking rods 225 whichare aligned with and screwed into threaded holes in the locking system270. In this secured position, the adapter bed support assembly and/orthe distributor may be removed from the column for maintenance once thefixing means are released, release being effected by removal from theexterior face of the column following removal of the nozzle 211 asdescribed above. Once maintenance has been carried out on the column(e.g. the bed support 221 has been replaced), the column 210 is madeoperational again by reversing the above procedure: the adapter assembly215 is released from the locking rod 225 and lowered by use of cylinders234, and then reconnected to the column tube 212 by replacing the nutswhich join the adapter flange 217 to the upper column flange 213 a.

Maintenance or service is carried out on the bottom distributor 266 orbase assembly 263 by releasing the tube 212 from the base assembly 263and lifting the tube 212 and adapter assembly 215 with the aid of thedrive system. The bolts on the lower flange 213 b of the column tube 212which join it to the bottom backing plate 264 are removed. The columntube 212 and adapter assembly 215 are then lifted by means of the drivecylinders 234. The tube 212 and upper adapter assembly is secured inposition above the base with the cylinder brackets 236 by screwinglocking bolts through holes aligned in the locking pin 270, bracket 236and cylinder 234.

The bottom nozzle 270 is then disconnected from the back plate 264 anddistributor 266. The nozzle 270 is removed together with the distancering 235, to allow access to release the fixing means 269 which may bein the form of a nut. The nut 269 is removed from the exterior face ofthe backing plate 264, i.e. the face distant from the cavity 222, andthus eliminates operator exposure to a suspended or supported load. Ifadditional releasable fixing means, such as bolts inserted through thebacking plate, distributor and bed support assembly as described aboveare present, these must be removed from the exterior face of the backingplate. The interior of the column may now be accessed for maintenance orservice, such as the replacement or cleaning of the bed support 268and/or O-rings. To return the column to an operational mode, the aboveprocedure is reversed.

FIG. 4 a is a schematic front view of a column in accordance with theinvention. The column 310 is supported on legs 304 and has a baseassembly 363 separated from an adapter assembly 315 by a tube 312. Thesecomponents are made of strong, inert materials which are approved forGMP within the pharmaceutical industries, such as stainless steel. Inthe figure, the base assembly 363 and adapter assembly are connected toa drive system which takes the form of three hydraulic cylinders 334. Itwill be understood that in other embodiments, different drive systemsmay be used to raise and lower the column, such as those powered bycompressed air or electricity. Furthermore, it is not essential thatthree cylinders are used, in some cases one being sufficient. The column310 has a top nozzle 311 and a bottom nozzle for the introduction ofliquids into the column. An electrical unit 378 for controlling thedrive system is also shown.

FIG. 4 b is a side sectional view of the column of FIG. 4 a showing oneof the hydraulic cylinders 334 in cross section. The cavity 322 forcontaining the bed of chromatographic media can be seen in crosssection. The liquid inlet 305, 375 and outlet 306, 376 of the top 311and bottom 372 nozzle are shown, for the introduction and removal ofliquids from the column 310. The cylinder 334 is connected to the baseassembly (comprising backing plate 364, distributor 366 and bed supportassembly 368) and the adapter assembly 315 (comprising backing plate320, distributor 331 and bed support assembly 321).

FIG. 4 c is a top plan view of the column of FIG. 4 a which shows thethree hydraulic cylinders 334 and nozzle 311 with liquid inlet 305 andoutlet 306.

To raise the adapter assembly 315 for maintenance purposes, the nutsunder the upper column flange, which join the adapter 315 and columnflange 313 a, are loosened and removed. The drive system then lifts theadapter assembly 315 by means of the hydraulic cylinders 334. Theadapter assembly 315 is raised until the locking bolts are opposite thethreaded holes in the hydraulic cylinders 334 and the bolts screwed into secure the assembly in the service or maintenance position (see FIG.3).

FIG. 5 a is a front perspective view showing the adapter assembly 415raised and secured into position to provide a gap 427 for access to theinterior of the column for service or maintenance. The column 410 has adrive system comprising three hydraulic cylinders 434. The adapter bedsupport mesh 428 of the bed support assembly, the distributor 431 andthe backing plate 420 are now visible; the bed support assembly can beunfastened from the distributor 431 and the backing plate 420 byreleasing the fixing means (not shown) without accessing the gap 427. Inorder to describe this process, reference is made to FIG. 4 in that thenozzle 311 is first removed to provide access to remove the retainingnut (not shown) which secures the backing plate 320, distributor 331 andbed support assembly 321 without accessing the gap 427. The fixing nutis removed from the exterior face of the backing plate 320.

FIG. 5 b shows release of the fixing means from the backing plate 420side of the adapter assembly using a spanner 446. The fixing means (inthe form of a retaining nut, obscured by the spanner) secures thebacking plate 420 to distributor and the adapter bed support assembly.

The bed support mesh 428 of the bed support assembly 421 is heavy andrequires the use of a special handling device to lift it once it hasbeen separated from the adapter assembly.

An embodiment of the handling device 580 is shown in FIG. 6. The device580 is in the form of a trolley or cart with a central pillar 581supported on frame 582 having legs 583. The device 580 is made ofstrong, inert materials; such materials include, but are not limited to,stainless steel and other materials which are suitable for use in a GMPenvironment typical of the pharmaceutical industry. Extendable arms 585a, b, c project from the pillar 581 and can be raised or loweredrelative to the pillar 581 by mechanical or other means. In theembodiment shown, the arms 585 a, b, c are raised or lowered by a manualjacking mechanism (not shown) adjacent to the handle 584 which providesthe means to steer or control the device. The arms 585 a, b, c aredesigned to bear the weight of the distributor or bed support and areextendable to the diameter of these components. While the embodimentshown has three arms 585 a, b, c, it will be understood that the deviceis not so limited and that other embodiments may have less than or morethan three arms (e.g. one, two, four, five) depending on the individualdesign. Holes 587 a, b, c at the extremities of the arms 585 a, b, c areprovided for bolting or securing of the distributor and/or bed supportto the arms for safety, particularly during transport. Pads (not shown)may be fitted to the arms 585 a, b, c to minimise any risk of damage tothe bed support/distributor when these components come into contact withthe arms. A raised, central element, 588 (typically of conical shape)for receipt of the central hole in the bed support or distributorprovides a means for centralising these components on the arms 585 a, b,c of the device 580. This element 588 may be fitted on either, or both,the upper or under side of the point where the arms 585 a, b, cintersect. In operation, the distributor and/or bed support is eithersuspended from the arms 585 a, b, c or supported on the arms. Pivotalwheels 586 allow easy movement and manoeuvrability of the handlingdevice 580. In the embodiment shown, the movement of the device 580 andthe raising/extension of the arms 585 a, b, c are by manual means, butit will be understood that other embodiments are possible whichincorporate powered systems (e.g. electrical, pneumatic or hydraulicsystems) to drive the device 580 and lift/lower the arm 585. It willalso be understood that in other embodiments of the handling device (notshown), arm 585 a is capable of pivoting or rotation around pillar 581to enable the arms 585 b and c to access a narrow gap between any twocylinders (e.g. 434 of FIG. 5 a) and remove/insert a bed assembly and/ordistributor which have a diameter which is greater than the distancebetween any two cylinders in the column (e.g. 434 of FIG. 5 a).

The operation of the device 580 in removing the bed support is shown inFIG. 7 to 9.

FIG. 7 a and FIG. 7 b are perspective views of the column of FIG. 5showing the handling device of FIG. 6 supporting the bed support mesh628 on one or more arms 685. The arms 685 are raised into position belowthe bed support mesh of bed support assembly 621, care being taken notto damage the mesh on the bed support by positioning the pads (notshown) on the arms 685 of the handling device 680 under the outer rim ofthe bed support mesh, and then gently raising the arms 685 up to the bedsupport. Once the arms 685 are in position, the nuts on the threadedrods 633 that go through the back plate 620 and distributor 631 into theouter perimeter of the bed support 621 are loosened and the bed supportassembly can be removed on the handling device. The rods 633 areinitially loosened with a spanner and finally removed by hand. As can beseen from the figures, the removal of the rods 633 is carried out fromthe exterior face of the backing plate 620 without accessing the gap andthus without exposing the operator to a suspended or supported overheadweight.

FIG. 8 a and FIG. 8 b are perspective views showing the removal of thebed support assembly in the form of the bed support mesh 728 on thehandling device 780 from the column 710. In FIG. 7 a the mesh 728,supported on the arms 785 of the device 780, is removed from the column710 without substantially tilting the mesh 728. The device 780 can thenbe moved away from the column (FIG. 8 b) and the arms 785 lowered inorder that the mesh 728 can be cleaned or replaced. Maintenance orservicing the column may now be carried out as required. For example,the screen 728 may be cleaned or replaced, O-rings replaced and/or thedistributor 731 may also be removed for cleaning.

To return to an operational mode, the above procedure is simplyreversed. The bed support/screen and/or distributor is returned to thecolumn and affixed to the backing plate, the nozzle reattached, theadapter assembly lowered and bolted to the column tube.

Access to the bottom bed support and interior of the column will now bedescribed with reference to FIGS. 9 to 13. To access the bottom bedsupport, the tube is released from the base assembly by unscrewing thebolts that join it to the base and then lifting the tube and upperadapter assembly with the hydraulic cylinders.

FIG. 9 a shows a column 810 as previously described in FIGS. 3 to 5 andFIGS. 7 and 8. The bolts on the lower flange 813 b of the column tubewhich fasten the tube 812 to the bottom backing plate 864 are loosenedand unscrewed. The column tube 812 and adapter assembly 815 are liftedby the hydraulic cylinders 834 of the drive system until the holeindicated by ‘A’ is opposite the hole indicated by ‘B’ in the inset ofFIG. 9 a. Locking bolts 837 are then introduced into the aligned holesin the locking pin 870, bracket 836 and cylinder 834 to secure the tubeand adapter assembly in position (FIG. 9 b). After removal of the boltssecuring the tube 812 to the bottom backing plate 864, maintenance cannow be carried out on the column in the gap 827 created by raising thetube and adapter assembly.

FIG. 10 shows the column 910 with the tube 912 raised and mechanicallylocked to the cylinders 934 in readiness for maintenance. The bottomnozzle (not shown—see 272 in FIG. 3) is first removed from the backplate 964 by unscrewing the retaining bolts. The retaining nut (orfixing means) which fastens the bed support assembly 968 to thedistributor 966 and the backing plate 964 is released from the backingplate 964 side of the column 910. If additional fixing means arepresent, such as bolts (not shown) which fasten the bed support to thedistributor and the backing plate, and are located on the perimeter ofthe backing plate, these are released from the backing plate face of thecolumn.

The bed support 968, 1068 can now be removed from the column by use ofthe handling device as shown in FIG. 11 a and FIG. 11 b. The handlingdevice (as described in FIG. 6 above) 1080 is wheeled into positionwhere the arms 1085 are a few centimetres above the bed support 1068.The bed support 1068 has a number of threaded holes that correspond tothe holes used to bolt the bed support to the backing plate 1064. Thearms 1085 of the handling device 1080 have holes through which bolts arescrewed into the bottom bed support 1068; these holes are aligned tothose of the bed support 1068 and bolts affixed to secure the bedsupport to the arms 1085. Once attached, the bed support 1068 can beremoved from the column by raising the arms 1085 a few centimetres andwheeling the handling device 1080 away from the column 1010. The bedsupport 1068 can now be cleaned or new O-rings replaced as necessary.Generally the bed support will be moved away from the column, as shownin FIG. 12, lowered onto a surface (such as a trolley or workbench) andreleased from the arms 1185 of the handling device 1180 to facilitatecleaning and servicing. The distributor (1066 in FIG. 11) can also beremoved and serviced in a similar manner using the lifting device.

Once maintenance or servicing has been completed, the column is returnedto an operational mode by simply reversing the process as describedabove. This involves replacing the bed support/and or distributor in thecolumn, affixing the components to the backing plate, reattaching thenozzle, lowering the tube and adapter assembly. FIG. 13 shows the column1210 of FIG. 11 connected to the hydraulic control unit 1290 with thetube 1212 lowered and ready to be bolted to the backing plate 1264.

All patents, patent publications, and other published referencesmentioned herein are hereby incorporated by reference in theirentireties as if each had been individually and specificallyincorporated by reference herein. While preferred illustrativeembodiments of the present invention are described, one skilled in theart will appreciate that the present invention can be practiced by otherthan the described embodiments, which are presented for purposes ofillustration only and not by way of limitation. The present invention islimited only by the claims that follow.

1. A method for conducting maintenance on a chromatography columncomprising the steps of: a) providing a chromatography columncomprising; a dispersion system comprising a nozzle including a mobilephase pathway connected to a liquid inlet; a tube with an adaptorassembly connected to a drive system, said adapter assembly moveablewithin a cavity of said tube in an operational mode; the adapterassembly comprising a backing plate, a distributor and a bed supportassembly fastened to each other by releasable fixing means, said drivesystem comprising one or more cylinders; a collection system opposingthe dispersion system; and one or more seals; b) disconnecting theadapter assembly from the tube; c) lifting the adapter assembly abovethe tube with the drive system to provide a gap for access therebetween;d) unfastening the bed support assembly from the distributor and thebacking plate by releasing the fixing means without accessing said gap;e) removing the bed support assembly from the column; f) conductingmaintenance on the column and/or the bed support assembly and/or saidone or more seals; g) returning the bed support assembly to the columnand fastening the bed support assembly to the distributor and thebacking plate; and h) lowering the adapter assembly with the drivesystem to an operational position within the tube and reconnecting theadapter assembly to the tube.
 2. The method of claim 1, wherein thefixing means are releasable from the exterior face of the backing plate.3. The method of claim 1, wherein the drive system comprises at leasttwo cylinders and the distance between any two said cylinders formaintenance access is greater than the diameter of the bed supportassembly.
 4. The method of claim 1, wherein said cylinders areexternally mounted to the column.
 5. The method of claim 4, wherein eachsaid cylinder is independently removable from the column.
 6. The methodof claim 1, wherein the step of removing the bed support assembly iscarried out without substantially tilting the bed support assembly. 7.The method of claim 6, wherein the step of removing the bed supportassembly without substantially tilting the bed support involves use of ahandling device.
 8. The method of claim 7, wherein said handling devicecomprises at least one arm and the method comprises supporting the bedsupport assembly on at least one arm of the handling device.
 9. Themethod of claim 1, wherein the step of conducting maintenance on thecolumn further comprises removing the distributor without substantiallytilting said distributor.
 10. The method of claim 1, wherein the columnfurther comprises a locking system, the method further comprising thestep of locking the adapter assembly with said locking system afterlifting the adapter assembly above the tube with the drive means.